• Asian-Australasian Journal of Animal Sciences
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• 제2권4호
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• pp.579-582
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• 1989

Previous experiments have shown that aqueous sodium silicate ingested in drinking water may modify the gastrointestinal uptake and(or) tissue retention of certain trace elements, including heavy metals. The present experiment tested, with a mineral balance trial using sheep, the hypothesis that dietary silicic acid could modify uptake, retention and(or) biological effects of dietary Cd. Twenty-four wethers were fed a fibrous diet of ground alfalfa hay and cottonseed hulls to which either 0 or 150 ppm Cd was added as $CdCl_2$ and 0, .5 or 1% silicic acid (as dry matter of the diet). Body weight, feed intake, excretion of urine (volume) and feces (weight), digestibility of dry and organic matter, retention of nitrogen, and packed cell volumes of blood were not affected by either Cd or silicic acid (P<.10). Cadmium decreased (P<.05) Ca retention and increased (P<.01) Mg retention. Silicic acid decreased (P<.05) K retention. Silicic acid failed (P<.01) to modify the retention of added dietary Cd. Body retention of K, Mn and Ni in response to silicic acid varied with Cd levels. If Cd is interfering with mineral retention, silicic acid may be effective in preventing this interference.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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• pp.192-197
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• 1996

An experimental study was performed to examine the feasibility of using silicic wastes as construction materials for civil structures, and investigate its utility as a replacement for the favored nature resource to prevent the economic loss. In order to achieve this objective, mechnical properties of concrete containing silicic wastes is tested by investigating the strength development through parameters of water-binder ratios replacement 10 percent ratio with respect to curting conditions. The effect of stringth development is investigated for curing conditions when silicic wastes of 10 percent of cement-binder ratios is containde. Comparision on compressive strength of normal concrete and concrete containing silicic wastes at 28 day is conducted. The concrete with silicic wastes have larger compressive strength than of normal concrete by about 20 percent, when cured at 80 degree. The wastes concrete using silica sand shows increased strength, fracture toughness, elastic modulus and strain than the normal concrete, although the silicic wastes concrete could be able to satisfy the generally required strength for conventional concrete structures.

• Asian-Australasian Journal of Animal Sciences
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• 제5권2호
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• pp.279-283
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• 1992

Eighteen wether lambs averaging 32 kg were used to determine the effects of dietary silica, added as silicic acid, on mineral metabolism. Lambs were fed 1200 g daily of a coastal Bermuda grass based diet supplemented with either 0, .5 or 1.5% silicic acid. A 7-d total collection of urine and feces was conducted after lambs had adjusted to the dietary treatments for 19 days. Urinary excretion of silica was higher (p<.01) in lambs fed added silicic acid. Ruminal soluble concentrations of manganese tended to be lower (p<.10) and apparent absorption and retention of manganese were lower (p<.05) in lambs supplemented with silicic acid compared to control lambs. Apparent absorption and retention of calcium were slightly lower (p<.10) in silicic acid fed lambs. No differences in urinary between lambs fed .5 and those given 1.5% silicic acid. Phosphorus, magnesium, iron, zinc and copper absorption and retention were not affected by treatment.

• 한국세라믹학회지
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• 제33권8호
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• pp.915-920
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• 1996

콜로이드 졸-겔법에 의해 초미립자 mullite 분말을 제조하였다. Al2O3의 출발 물질로 aluminum isopropoxide $[Al(i-OC_3H_7)_3]$을, $SiO_2$ 출발 물질로 규산 나트륨으로부터 tetrahydrofuran(이후 THF로 약기함)으로 추출한 규산을 사용하였다. 규산 나트륨은 규산을 생성시키기 위하여 묽은 황산으로 산성화시킨 다음 THF로 추출하였다. Mullite 분말은 졸-겔법에 의해서 Si 추출율와 Na 제거율을 조사한 규산과 aluminum isopropoxide로 부터 합성되었다. THF로 추출한 규산의 불순물 함량은 0.04% 이하이었다. 합성된 mullite 분말은 $3Al_2O_3{\cdot}2SiO_2$ 조성을 갖고 불순물의 함량은 0.0462% 이하의 직경 $0.05{\mu}m$ 정도의 결정상이었다. EDS, XRD, TG/DSC, SEM, FT-IR, ICP, TEM등으로 mullite 분말의 특성을 조사하였다.

• 한국입자에어로졸학회지
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• 제12권3호
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• pp.65-72
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• 2016

Nanoporous $SiO_2$ particles containing different pore volume and size were prepared from silicic acid by a spray pyrolysis. The pore size, pore volume and particle size could be controlled with varying the precursor concentration, reaction temperature, and amount of organic templates such as Urea and poly ethylene glycol (PEG). The pore size distribution, pore volume and specific surface area of as-prepared particles were analyzed by BET and BJH methods, and the average particle sizes were measured by a laser diffraction method. The nanoporous $SiO_2$ particles ranged $0.6-0.9{\mu}m$ in diameter were successfully synthesized and the average particle size increased as the silicic acid concentration increased. The morphology of nanoporous $SiO_2$ particles was spherical and pores ranged 1 - 40 nm in diameter were measured in the particles. In case of Urea added into silicic acid, it showed no much difference in the morphology, pore size and pore volume at different Urea concentration. On the other hand, when PEG was added, it was clearly observed that pore diameter and pore volume of the particles surface increased with respect to PEG concentration.

• 한국식품영양과학회지
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• 제26권6호
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• pp.1028-1032
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• 1997

Low-temperature crystallization method silver nitrate-impregnated silicic acid column chromatography were applied for the isolation of pure $\alpha$-linolenic acid(ALA) from perilla seed oil. ALA or 78% in purity(HALA; yield, 83%) was obtained from the fatty acid mixture(ALA, 65.7%) derived from perilla oil by the low-temperature crystallization method, when the mixture was frozen at -8$0^{\circ}C$ for 210min. ALA over 90% in purity(yield, 71%) was also obtained from HALA ethyl esters(ALA, 78%) by the silver nitrate-impregnated silicic acid column(100cm$\times$10cm, i.d.) chromatography. In addition, the silver nitrate-impregnated silicic acid could be semipermanently used for isolation of ALA, because $Ag^{+}$ ion was not dissociated from the stationary phase.

• 한국작물학회지
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• 제51권6호
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• pp.513-518
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• 2006

This study was conducted to investigate the relations between brown planthopper (BPH, Nilapavata lugens) resistance and specific organic acids (oxalic acid, silicic acid, and trans-aconitic acid) known as BPH sucking inhibitors on different rice varieties and/or lines. There were no specific relations between BPH resistance and the contents of oxalic and silicic acids in the rice plant tissues. However, the stronger the BPH resistance was occurred, the higher the content of trans-aconitic acid was contained in the rice plants. The relations between the injury rate of rice plant by BPH and the content of trans-aconitic acid in the rice plants were negatively correlated, which were -0.84 and -0.82 at 30 and 60 days after seeding, respectively. Therefore, the content of trans-aconitic acid in rice plant tissues might be utilized as an index for improving BPH resistance of rice varieties.

• 한국세라믹학회지
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• 제37권6호
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• pp.517-523
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• 2000

Effect of catalysts, which was catalyzed by acid(HCl and HNO3) and base(NH4OH), on characteristics of the mullite powders prepared by sol-gel methdo wa sinvestigated by XRD, TGA, SEm AND BET. As a result, weight loss as a function of catalysts was in order of HCl=32.6%>HNO3=25.44%>Non=24.0%>NH4OH=22.5%. The mullite powder dried at 100$^{\circ}C$ appeared spherical shape in acid catalyst and different shape in base catalyst, but sintering powder at 1400$^{\circ}C$ appeared very fine particle of 0.05∼0.1$\mu\textrm{m}$ regardless of catalysts. In all cae, the pore quantity, which was capable to adsoprtion, was decreased with increasing temperature. In base catalyst, no change of special surface area in mullite appeared.

• 한국식품과학회지
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• 제19권5호
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• pp.392-396
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• 1987

한국백삼의 유리페놀성 분획(free phenolic acid fr.)에서 phenolic acid의 분리 정제방법을 검토하였다. 먼저 silicic acid column에 의해 소분획으로 나누고 prep TLC 및 HPLC하여 정색반응 및 Pf차에 의해 phenolic acid로 추정되는 두 개의 화합물을 순수 분리하고, 결정을 얻어 UV, IR, MS, NMR로 그 구조를 밝힌 결과 ferulic acid와 vanillic acid로 확인되었다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.91.2-92
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• 2003

In order to elucidate influence of nutritional status on rice brown spot caused by Cochliobolus miyabeanus, rice cultivation soils and rice straws were collected from paddy fields where ice brown spot occurred severely, moderately, a little and none respectively. Rice plant materials were analyzed to measure inorganic nutrients in rice straws and rice seeds. Analysis of chemical properties of rice paddy soil showed that EC and contents of available phosphate, cation and silicic acid in soil with severe infections were lower than those in healthy soil. This result suggests that amount and holding capacity of nutrient contents in soils collected from paddy field with infection of C. miyabeanus are relatively low compared to those in soils collected from healthy paddy field. Analysis of inorganic nutrients in rice straws showed that amount of macronutrient elements such as silicic acids, available phosphate and total nitrogen, and micronutrients such as copper, iron and zinc in rice straws from paddy field with infection were lower than those in healthy soil. Especially amount of iron and silicic acid were very low in rice straws from paddy field soils with infection Amount of inorganic nutrients such as iron and zinc in rice seeds was the same trend as those of rice straws. These results showed that one of major factors affecting rice brown spot was amount of nutrient contents in soil and rice straw.